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Rewrite to remove dependence on rendezvous and its bizarre data structures. Makes it easier to use pthreads too. Still need to add code for non-pthreads systems. Just a checkpoint to switch work to another machine.
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 1 8ad51794 2004-03-25 devnull #include <u.h>

 2 b2cfc4e2 2003-09-30 devnull #include <unistd.h>

 3 a16e9f2d 2004-04-20 devnull #include <sys/time.h>

 4 b2cfc4e2 2003-09-30 devnull #include <sched.h>

 5 06bb4ed2 2004-09-17 devnull #include <errno.h>

 6 8ad51794 2004-03-25 devnull #include <libc.h>

 7 b2cfc4e2 2003-09-30 devnull 

 8 06bb4ed2 2004-09-17 devnull static pthread_mutex_t initmutex = PTHREAD_MUTEX_INITIALIZER;

 9 06bb4ed2 2004-09-17 devnull 

10 06bb4ed2 2004-09-17 devnull static void

11 06bb4ed2 2004-09-17 devnull lockinit(Lock *lk)

12 b2cfc4e2 2003-09-30 devnull {

13 06bb4ed2 2004-09-17 devnull 	pthread_mutexattr_t attr;

14 b2cfc4e2 2003-09-30 devnull 

15 06bb4ed2 2004-09-17 devnull 	pthread_mutex_lock(&initmutex);

16 06bb4ed2 2004-09-17 devnull 	if(lk->init == 0){

17 06bb4ed2 2004-09-17 devnull 		pthread_mutexattr_init(&attr);

18 06bb4ed2 2004-09-17 devnull 		pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_NORMAL);

19 06bb4ed2 2004-09-17 devnull 		pthread_mutex_init(&lk->mutex, &attr);

20 06bb4ed2 2004-09-17 devnull 		pthread_mutexattr_destroy(&attr);

21 06bb4ed2 2004-09-17 devnull 		lk->init = 1;

22 06bb4ed2 2004-09-17 devnull 	}

23 06bb4ed2 2004-09-17 devnull 	pthread_mutex_unlock(&initmutex);

24 b2cfc4e2 2003-09-30 devnull }

25 b2cfc4e2 2003-09-30 devnull 

26 06bb4ed2 2004-09-17 devnull void

27 06bb4ed2 2004-09-17 devnull lock(Lock *lk)

28 b2cfc4e2 2003-09-30 devnull {

29 06bb4ed2 2004-09-17 devnull 	if(!lk->init)

30 06bb4ed2 2004-09-17 devnull 		lockinit(lk);

31 06bb4ed2 2004-09-17 devnull 	if(pthread_mutex_lock(&lk->mutex) != 0)

32 06bb4ed2 2004-09-17 devnull 		abort();

33 b2cfc4e2 2003-09-30 devnull }

34 b2cfc4e2 2003-09-30 devnull 

35 06bb4ed2 2004-09-17 devnull int

36 06bb4ed2 2004-09-17 devnull canlock(Lock *lk)

37 b2cfc4e2 2003-09-30 devnull {

38 06bb4ed2 2004-09-17 devnull 	int r;

39 06bb4ed2 2004-09-17 devnull 

40 06bb4ed2 2004-09-17 devnull 	if(!lk->init)

41 06bb4ed2 2004-09-17 devnull 		lockinit(lk);

42 06bb4ed2 2004-09-17 devnull 	r = pthread_mutex_trylock(&lk->mutex);

43 06bb4ed2 2004-09-17 devnull 	if(r == 0)

44 06bb4ed2 2004-09-17 devnull 		return 1;

45 06bb4ed2 2004-09-17 devnull 	if(r == EBUSY)

46 06bb4ed2 2004-09-17 devnull 		return 0;

47 06bb4ed2 2004-09-17 devnull 	abort();

48 b2cfc4e2 2003-09-30 devnull }

49 b2cfc4e2 2003-09-30 devnull 

50 b2cfc4e2 2003-09-30 devnull void

51 06bb4ed2 2004-09-17 devnull unlock(Lock *lk)

52 b2cfc4e2 2003-09-30 devnull {

53 06bb4ed2 2004-09-17 devnull 	if(pthread_mutex_unlock(&lk->mutex) != 0)

54 06bb4ed2 2004-09-17 devnull 		abort();

55 b2cfc4e2 2003-09-30 devnull }